AITA for Being Furious with My Pregnant Wife Over a Prank?

I’m 31M. I’ve been with my wife, Lisa, since college, and she’s currently seven months pregnant with our first baby.

Lisa has a witty sense of humor and likes to play jokes on me. For instance, she enjoys passing off fake facts and stories as real to see if I’ll believe them. Lisa was a theater kid, so she’s great at acting and selling these stories. I used to fall for her pranks all the time since I’m pretty gullible, and she’s very convincing. However, now that I’ve been with her for so many years, I can usually tell when she’s messing with me. She’s upped the antics over the years, so she occasionally still gets me to believe one of her jokes.

Today, when I got home from work, Lisa had tears in her eyes and told me she needed to talk about something serious. I was genuinely worried and immediately sat down with her. I asked several times what was wrong, but she kept saying it was hard to talk about and that she was terrified I’d leave her. I kept pressing, and she eventually told me she’d had an affair with her boss several months ago and wasn’t sure if the baby was mine. I asked if she was serious, and she said she was 100% serious, then started crying even harder.

I got up, started pacing, and tried to gather my thoughts. After a few minutes, Lisa burst into laughter and said she was just joking. I was furious.

I told her it wasn’t funny at all to make jokes about cheating or about the baby not being mine. Lisa then said she was surprised I believed that particular prank and not others she’d tried. She said she couldn’t believe I’d actually think she’d cheat on me. Then she got teary and asked why I didn’t trust her.

I asked how I could trust her after she pulled a prank like that, managed to cry while telling me, and kept the act going even though I was visibly upset. Lisa said it was harmless and that I was blowing things way out of proportion. She kept questioning why I didn’t trust her, and I told her I needed some space.

I ended up going to a speakeasy and have been away from the house since, even though Lisa has called me several times. I know it was a prank, but I think this joke went way too far, especially with the tears. I was clearly upset (as anyone would be), and she should have stopped once she realized I was actually believing it. Usually, Lisa’s jokes are funny, but this one really affected me for some reason.

AITA, and am I overreacting? I feel bad because she’s very pregnant with our child, and I don’t want to stress her out, but I need some space right now.