Is it normal to get more horny when paying girlfriend for sex?

i mean , I can get sex for free from my girlfriend, but it usually turns me on more if I pay her money to have sex with me, sometimes she goes and buys sexy lingerie or shoes with the cash I give her, I am 10 years older than her but she has a good job and she makes more than me, I guess I'm kinda jealous or insecure about that, but it also makes me horny o include a financial aspect to our relationship, psychologically speaking, sometimes I call her sugar baby baby and she calls me sugar daddy, she has plenty of her own money to spend, but the fact that she persuades me to fork over my paycheck turns me on like no other. I like the feeling of pretending to be a millionaire and seducing her with my bank account even though I'm broke in real life. One time I walked in on her with me wearing only my boxers and I asked her if she was impressed with my big bulge, and she said she preferred the big bulge in my pockets, and that comment turned me on so much.