I am lucky on that point! He has been an active, athletic person his whole life, and he loves going to the gym. He's having fun going together becauseit's good time for us as a couple, and now that I've learned how to lift it's fun. He definitely has more strength training experience, but I am the nerdy one who likes to research programming and exercise physiology, so it's a good balance.
He's also one of those people who never struggles to lose fat, lucky guy. He is an ecto type who worked really hard to gain muscle mass. Photos of him as a young man show a fit but quite skinny guy. His younger brother still looks that way, but years of training and eating have paid off for my partner. It's a great example of activating genetic potential. He's a healthy, strong, fit man, in better shape at 40 than many guys half his age.