Boyfriend keeps putting money in my bag

I have money so I don't get why he's doing this but everytime I get home from seeing him I'll find money in my bag. Like 5-10 dollars everytime and we've been together for 2 yrs and the first time I called him and I was like "did u leave money in my bag?" He said "no? I gave it to you don't you remember?" I said "noooo?" And he said "well you're welcome" and started laughing. Dude just leaves money in my bag all the time lol like is this my payment for being a nice girlfriend 😂 I get an allowance