My girlfriend is rich.

So me (18m) and my girlfriend (25f) grew up totally different

The average 25 year old usually wouldn't bother dating a teenager....

she took me out on very very fancy restaurants

Also not really a location most teens/early 20s would take their date...

but I wish we could go to a restaurant where is also possible for me to pay the meal ya know ?

Sit her down, tell her that.

I just don’t know how to tell her this because she enjoys to take me out, I’m not saying I don’t like it but sometimes it’s really too much.

You can simply state that this early on, you'd like things to be more balanced, and that you'd like to do some activities etc. on your budget too.

/r/relationship_advice Thread