Sisters boyfriend has tinder profile... what to do?

[whateva234]

They have been together longer than the app has been around AND he was active today. Should I tell my sister/how?

[bomba78]

I would confront him first and give him the chance to offer some explanation. Give him a deadline to clear things up, before telling your sister.
make some screenshots for your backup just in case

[Yeatts]

Don't tell her show her. That way she will have no choice but to believe you. After that it's something that she needs to work out with him. It is better she finds out now rather then later.

[jannette723]

Tinder isn't just for hooking up. Maybe he's looking for new friends