Planning a trip with my SO who makes less than me is difficult... I don't mind paying for extras so we can enjoy it, but then he feels bad if I offer. But hell... It's for me as much as it is for him.

I've been in your SO's shoes before....just gotta suck it up!

Just say "you can pay me back in other ways ;)"

I would be honest with him, it's 2016 he needs to realize that money does not equate love. You want a fun vacation and each of you is paying what you can, this time around you pay more sometime in the future roles may be reversed and he would pay more. If he think it's OK for him to pay more that is just sexist and limiting vacation options due to an outdated ideal.

Can you use your points for airfare/hotels? You can call that "free" and just split money for incidentals.

Cake momma!! I got one of those!! I felt bad/guilty at first too, but then I realized that I would be holding her back from enjoying her vacay to the fullest. I also realized that we would be together forever and it would eventually even out. Maybe not monetarily but in working on the house, etc. So now I just enjoy the ride.