I think your friend has ishoos and needs to stop and think about what a baby of this age needs, and that is;
"The newborn baby has only three demands. They are warmth in the arms of its mother, food from her breast, and security in the knowledge of her presence. Breastfeeding satisfies all three." - Dr. Grantly Dick-Read
That she is going for nights out etc and likes to pass her baby around for other people to look after and feed says more about the lack of a bond she has with her baby than it does about your DS's natural desire to be held and your contentment in holding him.
He's not clingy he's normal. She's the one who needs to get more in touch with her own baby, not you who needs to put yours down. It's the old "get your life back" crap isn't it.
Oh, by the way, as he gets older he'll become a more efficient feeder and not need to feed as often as he probably does at the moment (taking into account that he's probably just had/having his 6 week growth spurt/feeding frenzy!) so you may find that he won't feed for ages and ages, and his fees will even out and get more spaced apart. You won't need to wean him at 17 weeks, ignore your HV, she's clearly not had any recent training on infant feeding and introducing solids, but definitely needs to!!
He'll probably have another growth spurt at about 12 weeks, and then another around 18-20 weeks, and then settle again before you start him on solids at about 6 months or so.