Wife is pissed

getting married this year. been together 3 1/2years. She was ok with the original idea of buying the car because i convinced her it would be practical( ya know in case one of our other cARS decided to break we could use the scamp). what i DIDN't tell her was that as soon as i can i'm gna tear it apart and drop a $6K motor in it....thats when she flipped...bought her a $3300 bed set. $4000 engagement ring. planning a $10k wedding. yet i'm still in the dog house...i don't understand it...but lemme tell ya the motor is being built..lol