Not as nefarious as it sounds I promise!
We viewed a house last year and fell absolutely in love with it, put in an offer that was accepted but then ran into a mortgage issue (a CCJ that I was completely unaware of and has subsequently been set aside by the court) which meant we had to pull out. We were gutted but moved on.
Today the property has reappeared on RightMove 
We are currently in rented and in a good position. The agent wants offers in by Monday lunchtime and my mortgage broker is currently working feverishly to get a DIP in place (mine ran out 2 days ago!)
For boring reasons the mortgage and house will be completely in my name and completely funded by me - DH is 100% aware of this and in complete agreement. There is no reason at all for him to be involved in the purchase process in any way (we've recently had a further purchase collapse and his only involvement with that was to view it with me)
Would it be utterly mad to go ahead (if my offer is accepted) in secret and surprise him on completion day with the keys?
On paper it sounds great, if perhaps a bit Instagram worthy (I wouldn't be posting videos or anything!) DH and I still talk wistfully about the house and we are both aware that our current rental is not a long term solution. I wouldn't consider doing it if he hadn't seen the house but he's viewed it twice already and loved it.
On the other hand it's a big surprise to pull off 