Nice to meet you. Make yourself at home. I'm taking off my pants.
That is strange to say to someone.
I see nothing wrong with that.
It is weird to take your pants off when you meet people. You may be comfortable but other people with take it the wrong way.
But girls don't seem to mind when I do it.
I think the problem is that you think they don't mind when in fact they do. It's also creppy.