Vegans?

OK my fiance and I have been together a little over 5 years 2 years engaged and we have both me he some changes in our diets he is now vegan and I'm Vegetarian and have been for 2 years now. I have noticed a huge change in our sex life he already lasted pretty long but now it's like a marathon(not to complain😊). Is this just me or is this like a vegan dick thing lol.