Please -need advice.

For some time now, i have suspected my wife of cheating on me. I get the usual signs like when the phone rings and i answer it, the caller just hangs up and she's been going out with 'the girls' a lot lately. I tried to wait up for her when she comes home but i just end up falling asleep.
Anyway, last night about midnight i hid in the garage behind the boat. When she came home she got out of someone's car and she was buttoning up her blouse and straightening out her hair.
It was at that moment, crouched behind the boat, i noticed a hairline crack in the outboard engine mounting bracket. Is this something i can weld or do i need to replace it?

My wife wouls strangle me if i put Pics of her on here