John Barrowman's elderly mother Marion is in intensive care.
The 59-year-old actor has pulled out of GeekdCon in Louisiana this weekend in order to stay by his mother's side as she battles her illness.
He shared a video on Twitter, where he explained: "Hey everybody this is a message to everyone who is heading to Shreeveport Louisiana for GeekdCon.
"Unfortunately I'm gonna have to cancel this weekend my mother is still in intensive care, and I feel it's only appropriate that I'm here with her and my dad and the rest of the family.
"So I hope you understand, go and have a great time there's lots of guests coming have a wonderful Con.
"Support the LGBTQIA+ community, make some videos to tell my Mum to get better. I would love that and sport those flags and all the rainbow flags and post those videos so I can watch them.
"I'm sorry I was looking forward to coming but unfortunately circumstances mean that I can't so lots of love to everybody and have a great great time."
John had earlier pulled out of the Huntington Comic Toy Con to be with his mother.
John is very close to both of his parents and previously spent the COVID-19 lockdown with them at his home in Palm Springs.
And he has spoken of how supportive they were when he first came out as gay.
He said: "I remember my parents were in their bedroom getting ready to go out when I mustered up the courage to tell them.
"I was standing in the doorway and said, 'I’m prepared for you to throw me out. If you do, I’m going to walk out of that door with my head high and I’m going to live my life. It’s going to be unfortunate, because you won’t be a part of it, but I’m telling you because I want you to be part of my life. It’s going to be a great journey and I’m going to have an awesome time. I want you there and I need you there.'
"Then I said, 'I’m gay'. I burst into tears.
"My mum walked to the other side of the room, turned around and went, 'Well, I’ve known'.
"My dad just said, 'What you do in your bedroom is really none of your mother’s or my business. You’re our son. We’ll always love you. Of course we’re not going to throw you out, but it might take a little while for us to understand.'
"I said, 'I’m willing to teach you.' Dad said, 'OK. Can we go and get dinner at the country club now?'"
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