I'm going to use tinder with the intent of only chatting while still in a relationship
Why would you want to talk to other people when you're in a relationship already?
I'm going to make money by using tinder.
It's wrong to use a dating app while in a relationship. You should respect your partner's feelings more.
No I want to use this for fun and maybe eventually get a threesome.
Is your current partner okay with you doing this? You need their consent for a threesome, and you should make sure that they know what you're doing. Otherwise you'll end up hurting their feelings.