Should I block him from social media?

My brothers friend has a girlfriend but we do fancy each other as we’ve had a chat about things. We haven’t had sex but we do flirt a lot and we’ve had a cheeky kiss in the past. My brother doesn’t know this about me and his friend as we’ve decided to keep it between us. Obviously I would love to get to know him more but we can’t because there’s a 3rd party involved and I’m not a home wrecking whore. I get the feeling he has no intentions of ending things with his girlfriend any time soon even though he doesn’t seem all that in to her anymore.
But I’m not sure if I should just block him on social media (or would that cause more issues? ), move on & be respectful.
Should I block him from social media?
Post Opinion