yearling stallion with my 4yr old gelding

Question
Hello Melanie,
I rely rather heavily on some horse savvy friends since i rescued a mini shetland filly last year. This rescue has reignited my dormant passion for ponies after 38yrs. I just bought a lovely 4yr old gelding 1.41cms to keep miss mini 82cms company. Thing is my horse savvy friends urgently needed a temporary companion for their 1yr old ungelded colt and I was glad to return some favours...but i'm now very worried about my gelding's safety. The colt is horse and bigger than him. I was surprised that they just turned them both out into a field together on meeting. The colt seemed very mean and nasty to my unexpert eyes but they said all would be well because my pony did eventually shout and kick back !!! Do you think they are taking advantage of my utter ignorance ?? Is my gelding safe ?? i've had them separated after 24hrs together but this is not to the liking of these friends (my main concern is my boy's safety)Please advise
Many thanks in advance
Mary

Answer
I would not leave the two of them together.  If something happens to your horse, who is going to pay the vet bills, or worse the vet fee to destroy him and haul carcass away?

And you never turn two or more horses out together that don't know each other as that is way to get one seriously injured or killed.

I've seen horses run through fence, run until they coliced, chased into a hole, bit and kicked.

And their horse is stud too, which makes this all the more dangerous, both for your horse, and for anyone who has to go into pasture.

Keep your horse separated, and furthermore, if they don't geld that colt, he will be going after your filly too, breeding her, and possibly savaging her, and possibly attacking your gelding and killing him.

Your gelding does not need to be in with him, and honestly?  I'd be looking for some place else to keep them.