The couple separated in 2010 and Armisen confesses to U.S. shock jock Howard Stern their break-up was largely his fault.
The Smurfs star says, ""I think I was a terrible husband, I think I'm a terrible boyfriend.""
The couple dated for one year before tying the knot, and Armisen admits he probably rushed into things too quickly.
He explains, ""I want it all - fast. I want to be married... and then somewhere around a year, two years, I get freaked out.""
But instead of breaking things off himself, the 46 year old admits he sabotaged the relationship with the Mad Men star so he didn't have to confront his emotions: ""You sort of withdraw and you sort of get into all the things you think make you weird, like, 'I'm really into playing Xbox... (or my) record collection.' You sort of disappear into the things that you think are just your hobbies.
""It must be so shocking to the woman because you're this guy who is so super-attentive in the beginning... and you are, like, the best boyfriend in the beginning, and then you become the worst boyfriend. I feel bad for everyone I've gone out with.""
Armisen also opened up about his first marriage to English singer Sally Timms, insisting they wed ""more for her green card"" than out of love, and his recent brief romance with his former Saturday Night Live co-star Abby Elliott.
He continues, ""(We) just fizzled. (We ended on) so-so terms. Once in a while, it would kind of be a little weird at work, but I have to say for the most part it was fine.""