Ducati Sporting Club UK - Urgent advice needed.....

I really need advice on what could be a crucial decision.

I've suspected for some time now that my wife has been cheating on me.
The usual signs...phone rings, but if I answer, the caller hangs up.
My wife has been going out with the girls a lot recently, although when I ask their
names she always says, "Just some friends from work, you don't know them."

I sometimes stay awake to look out for her cab coming home, but she always
comes walking up the drive as I hear the sound of a car leaving, around the
corner, as if she has gotten out and walked the rest of the way.
Why? Maybe she wasn't in a taxi at all?

I once picked up her mobile phone, just to see what time it was. This caused
her to go completely berserk. She quickly grabbed the phone out of my hand
and cursed me hysterically, screaming that I should never touch her personal
property, then accused me of trying to spy on her.

Anyway, I have never broached the subject with my wife.
I think deep down I just didn't want to know the truth, but last night she went out again and I
decided to really check on her. I decided I was going to park my bike
next to the garage and then hide behind it so I could get a good view of the
street around the corner when she came home. It was at that moment,
crouching behind my bike that I noticed a small amount of oil leaking
from underneath.

So... is this something I can easily repair myself or do you think I should
take it back to the dealer?