Common Tit

This male Common Tit made me puzzle since a few days. I saw it before and wondered what happened to its tail, was it damaged, was there another animal hanging, a parasite maybe?
No to all, today I got a good shot and found out that they have 2 small tails at the hind-wing, so when folded up you see 4 tails waving in the wind, a surprising view, as also the two spots give the impression that it's a BF with two fronts....