How to respond to "Sorry, I'm busy."

Say when you ask a friend if he wants to hang out, and he responds like...

"Wanna hang out?"

"About to head out"

"Alright"

"Sorry bud!" or "Sorry man!"

For some reason I feel offended when they say "sorry". Something else like "Next time," or "Catch you later?" would be so much better.

Whenever someone says sorry when you ask them to hang out and they say just "sorry" with no follow-up, I feel like it's like the biggest shut down ever, like your second-tier.

How would you respond to a text from a friend saying "sorry"
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+1 y
Pretty good answers so far, I'd like to hear more.
How to respond to "Sorry, I'm busy."
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