Please, do not make yourself right at home.

A Manhattan woman’s new love turned out to be a real lout, who moved his piano and other belongings into her apartment without permission — then began a scary stalking campaign when she tried to break up with him, she claims in a lawsuit.

Human Resources exec Angela Seitzer had been dating Christopher M. McFadden for a “brief” time in January when he bizarrely moved the giant instrument, Moroccan rugs, multiple dressers and tables, a chair, kitchen appliances and more than a dozen boxes of belongings into her home, she charges in a Manhattan Supreme Court lawsuit.

Seitzer soon realized McFadden “fabricated his personal and work history,” “abused drugs,” and brought a “highly addictive prescription medication” into her home, she alleges in court papers.

“McFadden was a violent con man,” who also had previous arrests for assault and domestic violence going back to 2013, and once even bizarrely accused her of trying to steal his sperm, she claims in her lawsuit.

Seitzer quickly dumped her beau, and obtained three different orders of protection against him, as he harassed her by text, called her bosses at NBC Universal and “enlisted a cadre of shadowy figures” to message her, according to the legal filing.

The strangers even tried break into her apartment, claims Seitzer. McFadden eventually had friends remove his belongings from Seitzer’s home under the watchful eye of NYPD officers, she said.

She wants a court to bar him from any contact with her.

McFadden could not be reached for comment.