Dear Amy: I am a 23-year-old personal trainer. I’m good-looking and muscular and get hit on by older females.

I was seeing a 38-year-old; she is in a long-term relationship, but her man wasn’t satisfying her, and we were hooking up three or four times a week.

We went on a three-day bicycle trip last summer, and I got her pregnant with twins. (She forgot her birth control.)

Her man knows the whole story and is willing to raise the babies and make me their godparent. I am glad he is willing to do that.

I am currently seeing a 34-year-old beautiful, sexy, divorced girl, and we just found out I got her pregnant.

I don’t know if I should offer to marry her, but I am thinking about it.

Your advice?

Tempting Trainer

Dear Trainer: For someone whose professional expertise concerns the human body, you don’t seem to respect the longer-term ramifications of your fertility.

At the ripe old age of 23, and over the course of just a few months, you are now the prospective biological father of (at least) three children.

It’s vital that you grasp the basics of birth control, as well as the legal, financial and emotional repercussions and responsibilities of fathering children.

You are obviously catnip for cougar kittens, and — given how cavalier you are about offering up your muscular DNA for procreating — you don’t seem mature enough to become a father or a husband.

If you or your current or future sexual partners don’t want to raise children, always use a condom. Always. In fact, you might want to double up.

Get tested for STDs, and urge your sexual partners to do the same.

In terms of you offering to marry your girlfriend, I’ll put it this way: If she were writing to me, I would advise her not to become matrimonially entangled with you.

It’s great that she is gorgeous and sexy, but you don’t mention loving — or even liking — her.

Dear Amy: I suffer from major depression and social anxiety.

I’ve moved to a new state and am slowly making friends. I live alone in a studio apartment, work from home, and I’m struggling with feelings of loneliness.

I want to get a pet companion but I’m having a hard time deciding between a cat or a dog. I love both cats and dogs equally.

I think a dog will be the most helpful for me because I struggle with going outside and getting regular exercise.

I’m also introverted, so I’m hoping daily walks will help me meet new dog-loving friends. However, I’m not experienced and I’m very much a low-energy homebody.

I’m worried that having a cat will keep me in the same cycle of laziness as always.

I’m wondering if it is OK to get a dog in order to help me to become more active? What if it’s a complete failure and I still don’t change my habits? Is it best to just get a cat?

I don’t think I’d have the patience for a puppy, but a small adult dog might be good.

I’d appreciate your advice.

In Need of a Pet

Dear In Need: You already know the joy of having a cat companion, and so let’s talk about dogs.

Your reasons for wanting one (companionship, being forced to go outside) are legitimate, and are the same reasons many people choose dogs.

However, because you lack experience I would caution you to choose extremely carefully. Does your apartment building allow dogs? How easy would it be for you to take the dog outside three or four times a day, via stairs or an elevator?

Whether you go with a cat or a dog, I urge you to look for a small, quiet, calm older animal. Work closely with your local shelter and take lots of time to find the best fit for you.

My local shelter understands that adoptions do not always work out, and insists that any animal adopted from them can be returned to them, no questions asked.

Dear Amy: “Perplexed” wondered why her widowed friend continued to send holiday cards featuring photos of her with her husband, who has been deceased for several years.

No one who has lost a loving spouse would ever wonder about this choice. I appreciated that you suggested that these photos should be seen as a celebration, rather than as some morbid refusal to move on.

Wistful Widow

Dear Wistful: I’ve heard from many surviving spouses who agree.

You can email Amy Dickinson at askamy@amydickinson.com or send a letter to Ask Amy, P.O. Box 194, Freeville, NY 13068. You can also follow her on Twitter @askingamy or Facebook.