'Mikey asked his friend for a night out...'
His friend is boy, and straight.
Is it common to 'ask an ordinary friend out'? If not, should we necessarily use 'invite'?
Unless there's a regular occasion (like 'the first Thursday of every month is a "Boys' Night Out"), I'd say 'invite' was better. A 'night out' sounds a bit intimate. I'd expect to see either a venue or an event too. So 'Mikey invited his friend to a movie', or just 'Mikey suggested that he and his friend meet at the pub ["for a quick/swift half[-pint of beer means it'll be a short meeting; they don't have to drink beer for 'a swift half' to be appropriate]'