Infidelity

Id like to say yes BUT i have been in this situation with my sister (gez i had to think about whether i wanted to put that or not but here we go), DH saw her DF (of 13 years!!) with another girl and then we caught him out on a few things BUT we never told my sis because ...well....reasons that seem silly now and i feel quite stink about it but i thought that if somehow we were wrong then i wouldv totally caused crap for her .....(she found it in the end)

So id say yes but in reality i may not not sure if id want my friend to tell me either...