Eileen has allowed love interest Paul Kershaw (Tony Hirst) and his wife Lesley (Judy Holt) to stay with her in recent weeks, as the water pipes have burst at their own house. However, this has also meant Eileen taking on the responsibility of caring for Lesley, who suffers from dementia.
The factory worker finally snaps in this week's episodes, asking Paul to leave when he refuses to consider a care home for Lesley.
Cleaver told itv.com: "Eileen's getting pretty stressed. She obviously has very strong feelings for Paul and she wants to help out, but the reality of the situation is really kicking in.
"Being left to look after this lady, who you just never know what she's going to do from one minute to the next, is proving quite hard for her.
"I don't think she resents Lesley - I think she feels very, very sorry for her. But the actual day-to-day [situation of] living with it and dealing with it is frustrating. Paul is asking Eileen to look after Lesley more and more. They're leading separate lives. It's really making her start to wonder, what is she getting out of this?"
As revealed a few weeks ago, the situation comes to a head as Lesley does a disappearing act with Steve and Tracy's young daughter Amy.
Cleaver added: "There is a big panic, and people are not backward in expressing their feelings about the situation - which again, really makes Eileen question what she's doing in this situation and whether there is any future with this man.
"I think things are going to get a lot worse for Eileen before they get better."
> Coronation Street fans want happiness for Paul, says Tony Hirst
> Coronation Street spoiler pictures - Eileen returns home to a distraught Lesley
> Read more Coronation Street spoilers and news