Verified answer

No, 'cos her past is her past. It was way before you and her, and therefore, none of your soddin' business, really, and quite frankly, old son, you're bloody lucky chose to tell ya at all! She didn't have to, seeing as it was in the past, and you would never of found out, had she not told ya, so what's yer bloody problem?! So she's had a bloody threesome in the past?! So bloody what?! Deal with it, my son! Bloody well grow up and deal with it! Push her over this, and she's liable to lose her bleedin' temper, and be like: "**** you, ********! I'm off!", and dump yer sorry ****! Be warned, old son! Choice is yours! It's entirely up to you, pal!

if she never told you before and just now brought it up, no. if she had previously said it didn't happen and recently said it did, yes. you have the right, but that doesn't mean you should be angry. if it were me and my boyfriend lied about it i would be upset and disappointed, and kinda unsure about who i was dating, but i wouldnt let him know that until i was fully sure of how i felt about it. if she lied be angry she lied to you, but it was in her past... if she just didnt mention it then dont be mad, keep it to yourself.

it was in her past and she was trying to make you happy.

get over it and move on, besides, maybe she will have one with you.