https://github.com/xrg/behave-parallel

Yes, there is a plan to support parallel execution in the future.
BUT: I cannot make any commitments when this functionality will be provided.

Therefore, you are best served to use the suggested URL above (if it helps you).

Until the native parallel executions are implemented in Behave, I highly recommend checking out the BehaveX library. BehaveX is a wrapper that extends the Behave framework with additional features that can significantly improve the performance of your test suites.
Repo: https://github.com/hrcorval/behavex

Some of the key features include:

☑ 𝗣𝗮𝗿𝗮𝗹𝗹𝗲𝗹 test execution for improved performance

• Easy-to-read HTML test execution 𝗿𝗲𝗽𝗼𝗿𝘁𝘀 with embedded test metrics such as Automation Rate, Pass Rate, and Steps Executions|Duration|Reusability
  ☑ 𝗧𝗲𝘀𝘁 𝗹𝗼𝗴𝘀 per scenario
  ☑ 𝗠𝘂𝘁𝗲 test scenarios in build servers
  ☑ Improved 𝗱𝗿𝘆 𝗿𝘂𝗻𝘀: See the full list of scenarios in an HTML report
  ☑ 𝗥𝗲-𝗲𝘅𝗲𝗰𝘂𝘁𝗲 failing test scenarios

BehaveX is easy to use. Simply install the library and replace the "behave" executable with "behavex" (I recommend taking a look at the documentation as not all Behave arguments are supported yet, but the most important ones). Then, you can run your tests in parallel using the following commands:

▶ 𝚋𝚎𝚑𝚊𝚟𝚎𝚡 -𝚝 @𝚃𝙰𝙶 --𝚙𝚊𝚛𝚊𝚕𝚕𝚎𝚕-𝚙𝚛𝚘𝚌𝚎𝚜𝚜𝚎𝚜 𝟺 --𝚙𝚊𝚛𝚊𝚕𝚕𝚎𝚕-𝚜𝚌𝚑𝚎𝚖𝚎 𝚜𝚌𝚎𝚗𝚊𝚛𝚒𝚘
(𝘛𝘩𝘪𝘴 𝘤𝘰𝘮𝘮𝘢𝘯𝘥 𝘳𝘶𝘯𝘴 𝘵𝘩𝘦 𝘵𝘦𝘴𝘵𝘴 𝘸𝘪𝘵𝘩 𝘵𝘩𝘦 𝘴𝘱𝘦𝘤𝘪𝘧𝘪𝘦𝘥 𝘵𝘢𝘨(𝘴) (@𝘛𝘈𝘎) 𝘪𝘯 𝘱𝘢𝘳𝘢𝘭𝘭𝘦𝘭 𝘶𝘴𝘪𝘯𝘨 4 𝘱𝘳𝘰𝘤𝘦𝘴𝘴𝘦𝘴, 𝘣𝘺 𝘢𝘴𝘴𝘪𝘨𝘯𝘪𝘯𝘨 '𝘴𝘤𝘦𝘯𝘢𝘳𝘪𝘰𝘴' 𝘢𝘤𝘳𝘰𝘴𝘴 𝘱𝘢𝘳𝘢𝘭𝘭𝘦𝘭 𝘱𝘳𝘰𝘤𝘦𝘴𝘴𝘦𝘴)

▶ 𝚋𝚎𝚑𝚊𝚟𝚎𝚡 -𝚝 @𝚃𝙰𝙶 --𝚙𝚊𝚛𝚊𝚕𝚕𝚎𝚕-𝚙𝚛𝚘𝚌𝚎𝚜𝚜𝚎𝚜 𝟹 --𝚙𝚊𝚛𝚊𝚕𝚕𝚎𝚕-𝚜𝚌𝚑𝚎𝚖𝚎 𝚏𝚎𝚊𝚝𝚞𝚛𝚎
(𝘛𝘩𝘪𝘴 𝘤𝘰𝘮𝘮𝘢𝘯𝘥 𝘳𝘶𝘯𝘴 𝘵𝘩𝘦 𝘵𝘦𝘴𝘵𝘴 𝘸𝘪𝘵𝘩 𝘵𝘩𝘦 𝘴𝘱𝘦𝘤𝘪𝘧𝘪𝘦𝘥 𝘵𝘢𝘨(𝘴) (@𝘛𝘈𝘎) 𝘪𝘯 𝘱𝘢𝘳𝘢𝘭𝘭𝘦𝘭 𝘶𝘴𝘪𝘯𝘨 3 𝘱𝘳𝘰𝘤𝘦𝘴𝘴𝘦𝘴, 𝘣𝘺 𝘢𝘴𝘴𝘪𝘨𝘯𝘪𝘯𝘨 '𝘧𝘦𝘢𝘵𝘶𝘳𝘦𝘴' 𝘢𝘤𝘳𝘰𝘴𝘴 𝘱𝘢𝘳𝘢𝘭𝘭𝘦𝘭 𝘱𝘳𝘰𝘤𝘦𝘴𝘴𝘦𝘴)

The --𝗽𝗮𝗿𝗮𝗹𝗹𝗲𝗹-𝗽𝗿𝗼𝗰𝗲𝘀𝘀𝗲𝘀 option specifies the number of processes to use for parallel execution. The --𝗽𝗮𝗿𝗮𝗹𝗹𝗲𝗹-𝘀𝗰𝗵𝗲𝗺𝗲 option specifies the scheme to use for parallel execution. The supported schemes are 'scenario' and 'feature'.