Played by Antony Cotton, Sean will have a civil partnership next year to former lover Marcus Dent, claims The Sun.
Charlie Condou will reportedly return to the serial after three years. Marcus left the Street for London in 2008 following a bust-up with Sean.
"Bringing back Charlie is seen as a big platform for him and in particular Antony who is well liked and admired by the boss. When Marcus turns up in Weatherfield in the spring he is desperate to rekindle his romance," a source claimed.
"But having hurt him once, Sean is apprehensive until Marcus offers him commitment, with the future storyline leading to Corrie's first same sex marriage," the insider added.
Collinson has previously stated: "Coronation Street is an amazing platform. You can really make a difference to the way people think - and this show has always had a gay sensibility."