Isn't a point where after being with someone a long time, they are entitled to "half your stuff" ? Regardless of marriage and such.

My advice, take it or leave it :

1) Talk to her calmly about it and find out the crack.

2) If unsatisfactory, throw her out (unless it's a joint house, in which case, sell up and split the dosh)

3) Ring bert the player, and inform him she's all his and you wish them very well, and by the way, your sister say's hello

4) Rebuild your life.

P.S. If you need a shitload of porn, gimme a shout