Hope someone can give me a bit of feedback

We are off to Tenerife next Friday for a week - husband was going to book online car parking at Belfast International Airport.
Its giving us a good discount as we've used them a number of times before, however its offering us the use of the "Executive Lounge" for two adults at a cost of £30 extra (return)
Anyone ever done this? Is it worth the money for the facilities - what facilities are there in the Executive Lounge?
Also, we have our son travelling - would they just refuse him entry if the offer is "only" for two adults - or would there be the facility of paying for him to get in?
Sorry if this sounds a bit off the wall, but weve never used this facility before and just dont know whether to go for it or not.
