You can’t take your 71 yr odl father-in-law to be out on a MTB ride, there’s only 2 possible out comes.
1) He hands your skinny weak legged ass to you again and then it gives him even more ammo to question your manlyness/suitability to marry his “wonderful” daughter, thus letting everyone know when he does the father of the bride speach on your big day.
2) He takes up the challenge and being a man who regards himself as very fit and healthy (and apparently strong) fails big time and either nearly dies or actually does. Then your beautiful wife to be will walk out on you for killing/nearly killing her father and you have to use your understrength legs to walk to the pub every night.
Either way you loose, FAIL!! 😆 😆