Then I'm welcome. What do you mean?

According to the context, there are two different meanings:

1, one is to accept invitations, hospitality or goodwill from others. For example, when a friend invites us to dinner, we usually politely say "thank you, then I'm welcome" to our friend.

2, there is a meaning that when you can't stand it, you will fight back or fight back. For example, someone keeps scolding us. At this time, we can't stand it anymore and will say to each other, "If you do this again, I will be impolite."