There might be some hope

There is this bodybuilder/personal trainer who comes to my workplace. He is in his 50s. He looks younger and yeah he is really in great shape. He has brought his gf a few times. His gf is his age and nothing that I would imagine. Very plain, no make-up, almost obese and she has like 5 kids from her previous relationship. They have been together for some years.

The guy talks to me here and there. The other day they came by and spoke to me and his gf was happy because they were moving in together. She kept telling me how lucky she has been to have met him.

So I wonder, what could have brought them together? Don't get me wrong, I am happy for her and I can relate. He could have easily gone for someone half his years. But what could be some of the criteria where attractive men date ugly women? I also know that she is not rich. ​​​​