I'll just echo what every else here has said and just say don't lie to the wife.
1. She'll know
2. She'll know
3. She'll know
They always know. Take your beating like a man!
And next time, some advice: sell her on it. If she's really saying no, you might want to listen to WHY she's saying no as she may have a really good point. If not, she bought into it and no further beatings need occur!
Brief story: back in 1990 I wanted to upgrade the bass rig. Talked it over with my girlfriend who I was living with at the time. She said "I want to hear the choices". So I took her down to the music store I was working at, couple of hours before we opened, and I tried every single amp in the store for her that came even remotely close to what I was looking for. Then she said, pointing at the SWR, "what about that one?" I said, "honey, there's no way, it's awesome but it's too expensive." She made me play it. She stopped me after only about thirty seconds and said "don't waste your money with this other stuff, buy that one." "Really?" "Oh yeah. You won't have to buy another one ever again." She was dead on right about that.
We didn't make it long term, but we still get along and I STILL have that amp and gigged it as recently as six months ago, and it will be going into the studio with me next month. I finally bought a new micro head/neo cab rig this year, because it's getting too hard to lift the old cab. The 220/Goliath rig still is the best sounding amp I own.