About 6 weeks I adopted to lovely boy cats from a shelter. They're brothers, both about 15 months old. Tomorrow they get their top up vaccine so they get to go outside. They're desperate to get out and I'm desperate to open the windows (6 weeks of two cats in a smallish flat). But I'm so nervous about it. I'm convinced they won't come back. Any tips on managing the first release and helping use the lads use the cat flap. It's a magnetic one. Thank you.