I was contacted by text by a male colleague tonight (on my work phone, that's how he has my number). I was very surprised as we have a quick chat now and again but nothing out of the ordinary.
He is married so I've told him I didn't think it was a good idea we text as I didn't want anyone getting the wrong idea and I didn't want to upset his wife.
At first I thought I'd been rude as maybe he just wanted to make friends, but he has since replied (as I type) that he wouldn't tell anyone and his wife was out anyway.
So I think I've done the right thing and I won't be texting back